The investment-based distillery league table showed a return to favour for Balvenie which was up eight places, Lagavulin which rose 10 places in its 200th year, and Highland Park which climbed nine places.

“The stellar performers over H1 2016 have been Macallan 18 and 25-year-old indices, experiencing incredible six-month rises of 29% and 27% respectively,” said the report.

“We believe this is, in part, a result of the perceived decline in quality, and de-aging of contemporary Macallan bottlings, driving connoisseurs, collectors and investors to look to the secondary (auction) market to find the treasures they desire.”

The report warned collectors to be careful about an increase in fake Scotch hitting the market.

“The vast majority of the UK’s dedicated and knowledgeable whisky auctioneers are consistently policing the market where they have ‘eyes-on’ and can identify rogue sellers and/or bottles,” the report said.

“We urge caution against buying any rare/old bottles from websites where private vendors list their own bottles and there are no third party counterfeit checks in place.

“We have recently confirmed significant collections of Macallan as being 100% fake where they have been purchased via privately listed auction sites.”